Chief of the Foundry

Other artifact creatures you control get +1/+1.

Simulacrum Synthesizer

When Simulacrum Synthesizer enters, scry 2.
Whenever another artifact you control with mana value 3 or greater enters, create a 0/0 colorless Construct artifact creature token with "This creature gets +1/+1 for each artifact you control."

Thornglint Bridge

Thornglint Bridge enters tapped.
Indestructible
{T}: Add {G} or {W}.

Perilous Myr

When Perilous Myr dies, it deals 2 damage to any target.

Rustvale Bridge

Rustvale Bridge enters tapped.
Indestructible
{T}: Add {R} or {W}.

Thought Monitor

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
When Thought Monitor enters, draw two cards.

Grimclimb Pathway

Brightclimb Pathway

Brightclimb Pathway // Grimclimb Pathway

Myr Kinsmith

When Myr Kinsmith enters, you may search your library for a Myr card, reveal it, put it into your hand, then shuffle.

Myr Enforcer

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

Ghostfire Slice

Devoid (This card has no color.)
This spell costs {2} less to cast if an opponent controls a multicolored permanent.
Ghostfire Slice deals 4 damage to any target.

Goldmire Bridge

Goldmire Bridge enters tapped.
Indestructible
{T}: Add {W} or {B}.

Tidechannel Pathway

Barkchannel Pathway

Barkchannel Pathway // Tidechannel Pathway

Craterhoof Behemoth

Haste
When Craterhoof Behemoth enters, creatures you control gain trample and get +X/+X until end of turn, where X is the number of creatures you control.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Power Depot

Power Depot enters tapped.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast artifact spells or activate abilities of artifacts.
Modular 1

Mistvault Bridge

Mistvault Bridge enters tapped.
Indestructible
{T}: Add {U} or {B}.

Clock of Omens

Tap two untapped artifacts you control: Untap target artifact.

Lavaglide Pathway

Riverglide Pathway

Riverglide Pathway // Lavaglide Pathway

Leyline of Abundance

If Leyline of Abundance is in your opening hand, you may begin the game with it on the battlefield.
Whenever you tap a creature for mana, add an additional {G}.
{6}{G}{G}: Put a +1/+1 counter on each creature you control.

Concealed Courtyard

Concealed Courtyard enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {B}.

Tanglepool Bridge

Tanglepool Bridge enters tapped.
Indestructible
{T}: Add {G} or {U}.

Roaming Throne

Ward {2}
As Roaming Throne enters, choose a creature type.
Roaming Throne is the chosen type in addition to its other types.
If a triggered ability of another creature you control of the chosen type triggers, it triggers an additional time.

Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Myr Battlesphere

When Myr Battlesphere enters, create four 1/1 colorless Myr artifact creature tokens.
Whenever Myr Battlesphere attacks, you may tap X untapped Myr you control. If you do, Myr Battlesphere gets +X/+0 until end of turn and deals X damage to the player or planeswalker it's attacking.

Vexing Bauble

Whenever a player casts a spell, if no mana was spent to cast it, counter that spell.
{1}, {T}, Sacrifice Vexing Bauble: Draw a card.

Mana Vault

Mana Vault doesn't untap during your untap step.
At the beginning of your upkeep, you may pay {4}. If you do, untap Mana Vault.
At the beginning of your draw step, if Mana Vault is tapped, it deals 1 damage to you.
{T}: Add {C}{C}{C}.

Slitherbore Pathway

Darkbore Pathway

Darkbore Pathway // Slitherbore Pathway

Three Steps Ahead

Spree (Choose one or more additional costs.)
+ {1}{U} — Counter target spell.
+ {3} — Create a token that's a copy of target artifact or creature you control.
+ {2} — Draw two cards, then discard a card.

Securitron Squadron

Squad {3} (As an additional cost to cast this spell, you may pay {3} any number of times. When this creature enters, create that many tokens that are copies of it.)
Vigilance
Whenever a creature token you control enters, put a +1/+1 counter on it.

Blooming Marsh

Blooming Marsh enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {G}.

Timbercrown Pathway

Cragcrown Pathway

Cragcrown Pathway // Timbercrown Pathway

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.

Razorverge Thicket

Razorverge Thicket enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {W}.

Mistgate Pathway

Hengegate Pathway

Hengegate Pathway // Mistgate Pathway

Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Comet Storm

Multikicker {1} (You may pay an additional {1} any number of times as you cast this spell.)
Choose any target, then choose another target for each time this spell was kicked. Comet Storm deals X damage to each of them.

Botanical Sanctum

Botanical Sanctum enters tapped unless you control two or fewer other lands.
{T}: Add {G} or {U}.

Myr Custodian

When Myr Custodian enters, scry 2. Then each opponent may scry 1. (To scry X, a player looks at the top X cards of their library, then puts any number of them on the bottom and the rest on top in any order.)

Sol Ring

Myr Galvanizer

Other Myr creatures you control get +1/+1.
{1}, {T}: Untap each other Myr you control.

Myr Convert

Toxic 1 (Players dealt combat damage by this creature also get a poison counter.)
{T}, Pay 2 life: Add one mana of any color.

Lodestone Myr

Trample
Tap an untapped artifact you control: Lodestone Myr gets +1/+1 until end of turn.

Sculpting Steel

You may have Sculpting Steel enter as a copy of any artifact on the battlefield.

Myr Propagator

{3}, {T}: Create a token that's a copy of Myr Propagator.

Spirebluff Canal

Spirebluff Canal enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {R}.

Glasspool Shore

Glasspool Shore enters tapped.
{T}: Add {U}.

Glasspool Mimic

You may have Glasspool Mimic enter as a copy of a creature you control, except it's a Shapeshifter Rogue in addition to its other types.

Glasspool Mimic // Glasspool Shore

Frogmyr Enforcer

Prototype {3}{R} — 2/2 (You may cast this spell with different mana cost, color, and size. It keeps its abilities and types.)
Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)

Copper Myr

Mirrorworks

Whenever another nontoken artifact you control enters, you may pay {2}. If you do, create a token that's a copy of that artifact.

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.

Silver Myr

Flusterstorm

Counter target instant or sorcery spell unless its controller pays {1}.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Copperline Gorge

Copperline Gorge enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {G}.

Darkslick Shores

Darkslick Shores enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {B}.

Arcbound Ravager

Sacrifice an artifact: Put a +1/+1 counter on Arcbound Ravager.
Modular 1 (This creature enters with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Drossforge Bridge

Drossforge Bridge enters tapped.
Indestructible
{T}: Add {B} or {R}.

Gold Myr

Great Furnace

Searstep Pathway

Blightstep Pathway

Blightstep Pathway // Searstep Pathway

Leyline Axe

If this card is in your opening hand, you may begin the game with it on the battlefield.
Equipped creature gets +1/+1 and has double strike and trample.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

Ancient Den

Razortide Bridge

Razortide Bridge enters tapped.
Indestructible
{T}: Add {W} or {U}.

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Iron Myr

Voltaic Construct

Plague Myr

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)
{T}: Add {C}.

Banish to Another Universe

Affinity for historic permanents (This spell costs {1} less to cast for each artifact, legendary, and/or Saga permanent you control.)
When Banish to Another Universe enters, exile target nonland permanent an opponent controls until Banish to Another Universe leaves the battlefield.

Shimmer Myr

Flash
You may cast artifact spells as though they had flash.

Darkmoss Bridge

Darkmoss Bridge enters tapped.
Indestructible
{T}: Add {B} or {G}.

Replication Specialist

Flying
Whenever a nontoken artifact you control enters, you may pay {1}{U}. If you do, create a token that's a copy of that artifact.

Urza, Lord Protector

Artifact, instant, and sorcery spells you cast cost {1} less to cast.
{7}: If you both own and control Urza, Lord Protector and an artifact named The Mightstone and Weakstone, exile them, then meld them into Urza, Planeswalker. Activate only as a sorcery.

Alloy Myr

Mockingbird

Flying
You may have Mockingbird enter as a copy of any creature on the battlefield with mana value less than or equal to the amount of mana spent to cast Mockingbird, except it's a Bird in addition to its other types and it has flying.

Consider

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
Draw a card.

Seachrome Coast

Seachrome Coast enters tapped unless you control two or fewer other lands.
{T}: Add {W} or {U}.

Doubling Season

If an effect would create one or more tokens under your control, it creates twice that many of those tokens instead.
If an effect would put one or more counters on a permanent you control, it puts twice that many of those counters on that permanent instead.

Starstorm

Starstorm deals X damage to each creature.
Cycling {3} ({3}, Discard this card: Draw a card.)

Age-Graced Chapel

Age-Graced Chapel enters tapped.
{T}: Add {W} or {B}.

Glasswing Grace

Enchant creature
Enchanted creature gets +2/+2 and has flying and lifelink.

Glasswing Grace // Age-Graced Chapel

The Mightstone and Weakstone

When The Mightstone and Weakstone enters, choose one —
• Draw two cards.
• Target creature gets -5/-5 until end of turn.
{T}: Add {C}{C}. This mana can't be spent to cast nonartifact spells.
(Melds with Urza, Lord Protector.)

Cyclonic Rift

Return target nonland permanent you don't control to its owner's hand.
Overload {6}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Urtet, Remnant of Memnarch

Whenever you cast a Myr spell, create a 1/1 colorless Myr artifact creature token.
At the beginning of combat on your turn, untap each Myr you control.
{W}{U}{B}{R}{G}, {T}: Put three +1/+1 counters on each Myr you control. Activate only during your turn.

Palladium Myr

Myr Retriever

When Myr Retriever dies, return another target artifact card from your graveyard to your hand.

Mycosynth Golem

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Artifact creature spells you cast have affinity for artifacts. (They cost {1} less to cast for each artifact you control.)

Myr Superion

Spend only mana produced by creatures to cast this spell.

Slagwoods Bridge

Slagwoods Bridge enters tapped.
Indestructible
{T}: Add {R} or {G}.

Seat of the Synod

Deduce

Draw a card. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Bojuka Bog

Bojuka Bog enters tapped.
When Bojuka Bog enters, exile target player's graveyard.
{T}: Add {B}.

Pillarverge Pathway

Needleverge Pathway

Needleverge Pathway // Pillarverge Pathway

Darksteel Citadel

Leyline of the Guildpact

If Leyline of the Guildpact is in your opening hand, you may begin the game with it on the battlefield.
Each nonland permanent you control is all colors.
Lands you control are every basic land type in addition to their other types.

Blackcleave Cliffs

Blackcleave Cliffs enters tapped unless you control two or fewer other lands.
{T}: Add {B} or {R}.

Leaden Myr

Inspiring Vantage

Inspiring Vantage enters tapped unless you control two or fewer other lands.
{T}: Add {R} or {W}.